I would have to agree with Lynn Seiser here. Maai is the "proper" or "right" distance. That means that it is "situational specific," and can only be known in strict accordance with one's actions and intent. In other words, we are talking about the necessary relationship that must be present between Space and Time in light of an intent to execute a given tactic and/or strategy. There is a constant fluctuation in the manifestation of these things but a harmonious relationship must always be present between them. So it would not be a matter of being at a safe distance and/or of being out of range unless those two things were your intended tactic. That is the best way to understand "maai" - in my experience.

As for Lee's ranges, I think the current understandings offered thus far are a bit too two-dimensional. Combat is a lot more dynamic. Thus it cannot serve us well to measure things in a way that only makes sense within a situation where we picture two men standing in front of each other at distance "X," and then watch them close in at varying degrees of "-X." I think this is important to realize no matter what one's art, but I think it is doubly important for one to understand when one's art makes ample use of the spiral in its tactical architecture. Aikido falls firmly within this parameter.

The spiral allows us to strike, kick, throw, trap, pin, etc., at "ranges" not even conceivable when one only understands maai two-dimensionally (linearly) in terms of "X" and the various forms of "-X." In other words, Aikido's spirals, I would suggest, make Lee's formula irrelevant. We do not train for one range, or even for four or five ranges. Spirals, in their three dimensional structure, which itself can travel along any given plane and/or curve, and that can also be enhanced by a fourth dimension of Time, have us addressing the various tactical limitations of a given basic in terms of range in a totally different way. We would be wiser to look more at that -- look at how and why that can happen and should happen -- why would should reject Lee's thesis outright.